Jaw type heat sealing machines



Sept. 26, 1961 Filed April 9, 1958 J. J. GREVICH ET AL JAW TYPE HEAT SEALING MACHINES MAIL s 9 Sheets-Sheet'l.

' III INVENTOR Jo/m J. rer/efi Pau/ 0 Jordan Sept. 26, 1961 A .1. J. GREVICH ETAL 3,001,457-

JAW TYPE HEAT SEALING MACHINES Filed April 9, 1958 9 Sheets-Sheet 2 INVENTOR L/0/7/7 J Grey/ch Pau/ 0 Jordan ATTORNEY Sept. 26, 1961 Filed April 9, 1958 J. J. GREVICH ET L JAW TYPE HEAT SEALING MACHINES 9 Sheets-Sheet 3 I INVENTOR John J. rewc/z Pau/ 0 Jordan ATTORNEY Sept. 26, 1961 J. J. GREVICH ETAL 3,001,457

JAW TYPE HEAT SEALING MACHINES 9 Sheets-Sheet 4 Filed April 9, 1958 INVENTOR John J. Grew/dz Pau/ O. Jordan ATTORNEY Sept. 1951 J. J. GREVICH ET AL 3,

JAW TYPE HEAT SEALING MACHINES Filed April 9, 1958 9 Sheets-Sheet 6 INVENTOR John J. Grzr/ch F/& 20 PQU/ Jam/an BY g QM TTORNEY Sept. 26, 1961 J. J. GREVICH ET AL 3,001,457

JAW TYPE HEAT SEALING MACHINES 9 Sheets-Sheet 7 Filed April 9, 1958 252 229 C--.- I T 1Z7; INVENTOR John J Grew/ch Z7] Paa/ 0. Jordan ATTORNEY pt- 1961 J. J. GREVICH ET AL 3,001,457

JAW TYPE HEAT SEALING MACHINES Filed April 9, 1958 9 Sheets-Sheet 8 INVEN TOR John J rewlc/z Pau/ 0 Jordan BY Qumha ATTORNEY Sept, 26, 1961 .1. J. GREVICH ETAL 3,001,457

JAW TYPE HEAT SEALING MACHINES Filed April 9, 1958 9 Sheets-Sheet 9 i 20 1a 2/ 1a Z4 Ea 3/ 305 307 INVENTOR John J. Grey/ch Paw/ Q Mar a a? ATTORNEY United States Patent C) 3,001,457 JAW TYPE HEAT SEALING MACHINES John J. Grevich, New Richmond, and Paul G. Jordan,

Hudson, Wis, assignors to Doughboy industries, Incorporated, New Richmond, Wis, a corporation of Wiscousin Filed Apr. 9, 1955, Ser. No. 727,437

21 Claims. ((1. 93-27) This invention relates to an improvement in jaw type heat sealing machines and deals particularly with an apparatus useful in heat sealing the open ends of a bag or the like and applying a folded label over the end of the bag or in applying a label to a previously sealed bag.

Various types of heat sealing machines have been produced including a pair of jaws which may be moved together to seal a pair of plastic sheets together. In some instances, such machines have been used to seal the open ends of bags and to apply a folded label to the bag end. One of the common difficulties with machines of this type have been that it is usually necessary to hold the bag during the heat sealing operation. As no means is provided for holding the bag during the sealing operation, it must be held by the operator until sealed to ensure the removal of the bag from between the jaws before the next bag is sealed. As a result, the number of bags which may be sealed in a predetermined time is quite limited.

It is an object of the present invention to provide a heat sealing machine of the type described which may operate much more quickly than other machines with which we are familiar. The operation of the apparatus is initiated by merely inserting the end of the bag to be sealed into position before the sealing jaws. When this is done, the apparatus automatically operates through a sequence of motions to fold the label over the bag, seal the open end of the bag, seal the label to the bag, punch a hole in the bag, stamp a code mark upon the sealed label, open the sealing jaws, forcibly eject the sealed end of the bag from between the jaws, and deliver a label into position to be sealed over the end of the next bag. As a result, the operator may release the bag as soon as the operation starts and may grasp another bag to be sealed so that this next bag may be brought into sealing position as soon as the previous bag is released.

A feature of the present invention resides in the provision of a device of the type described which includes a clamping member which engages the bag at the beginning of the cycle of operation and which holds the bag in proper position until the sealing operation is completed. As a result, both hands of the operator are free as soon as the cycle of operation starts.

A further feature of the present invention resides in the provision of a means for automatically aligning the edge of the bag with the label so that the label is centered with respect to the sealed end of the bag. In the past, it has normally been necessary for the operator to properly align the edges of the bag with the label in order to prevent the label from being sealed in laterally offset relation to the bag. In the present arrangement, a novel type of air switch is provided which is actuated by the edge of the bag as the bag is moved into proper alignment with the label. When the switch is actuated, the cycle of operation immediately starts and the clamping blade or bar immediately clamps the bag in proper position so that the bag and label are properly related.

A further feature of the present invention resides in the provision of a novel type of air switch which is sufliciently sensitive to be operated merely by the pressure of the edge of the bag against the switch. Bags of the type employed are normally made of thin plastic sheeting which may be kinked inwardly by a very slight pressure against the film. The air switch employed incorporates a very light blade or reed of flexible resilient material which may be moved into switch closing position by the extremely light pressure of the edge of the bag against the blade or reed.

A further feature of the present invention resides in the provision of a machine of the type described which is so constructed as to permit ready release of the bag at the completion of the sealing operation. The upper edge of the bag and the label is folded into doubled form by a folding blade which engages against the upper end of the bag and engages against the label intermediate its upper and lower edges. This blade forces the label into doubled form to enclose the upper edge of the bag. The blade is then removed from between the jaws and sealing pressure is exerted upon the jaws to clamp the label against the upper edge of the bag and to seal the parts together. At the completion of the sealing operation, the jaws are spread widely apart to permit the upper end of the bag to be readily ejected. At the same time, the folding blade and clamping bar move away from the jaws a distance sufficient to permit the upper end of the bag to fall free of the jaws between the jaws and the folding arm and clamping arm. At the end of the cycle, the jaws move together to a point where they are spaced apart a distance just sufiicient to permit the label and bag to be forced between the jaws by the folding blade. At the same time, the folding blade and clamping arm move toward the jaws so as to reduce the distance of travel of the clamping arm and folding blade when the next bag is inserted.

An added feature of the present invention resides in the fact that at the end of each cycle of operation the label feeding device moves a new label into position forwardly of the jaws in position to be folded and sealed to the next bag in the following cycle of operation.

Still another feature of the present invention lies in the provision of a switch mounted upon the clamping arm and normally projecting toward the jaws in position to be engaged by the edge of the next bag to be sealed. As the clamping arm is actuated to move toward the lower jaw and to clamp the bag between the lower jaw and the clamping arm, the switch is automatically retracted beneath the clamping arm so as to be out of the path of movement of the bag during the bag ejecting process. In this way, the switch is held out of the path of movement of the bag as it is ejected, thus preventing a false operation of the switch as the bag is ejected, thereby preventing an improper recycling of the apparatus before the next bag to be sealed is in sealing position. As soon as the ejection of the bag is completed, the switch automatically moves into projecting position for actuation by the next bag to be sealed.

Still another feature of the present invention resides in the provision of a simple and effective feed mechanism for removing labels from a magazine and delivering the labels into position forwardly of the sealing jaws. The feed mechanism includes suction cup means which pull the label forwardly from the magazine, swing the label downwardly to a proper elevation forwardly of the jaws, and then moves the label rearwardly toward the sealing jaws. This motion insures the free movement of the label as it is carried from storage position to sealing position.

An added feature of the present invention resides in the provision of an ejector associated with the lower jaw of r the machine and movable in a direction at generally right angles to the jaw. As the sealing jaws spread wide apart at the completion of the sealing operation and as the clamping bar and folding blade are disengaged from the bag, the ejector pushes the bag away from the jaws to release the sealed end frombetween the jaws, thus providing a positive ejection of the bags.

An added feature of the present invention resides in the provision of a simple and effective means of applying pressure to the labels in the label magazine and in adjusting the pressure as required.

. An important feature of the present invention resides in the provision of an adjustable spring means for resiliently urging the jaws together and in mounting this spring means at a point distant from the jaws. In normal service, one of the jaws at least is resiliently mounted by springs which are directly associated with the heated jaws. The heat of the jaws has a deleterious effect upon the springs. By mounting the spring means at a distance from the heated jaws, many previous difficulties are avoided.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of the assembled apparatus omitting the control box and air pump to simplify the illustration.

' FIGURE 2 is a front elevational view of the apparatus in readiness for use.

FIGURE 3 is a diagrammatic side view of the label feeding apparatus, much of the remaining structure being omitted to simplify the showing.

FIGURE 4 is a vertical sectional view through the main drive shaft and the cam shaft showing the relationship of the parts.

FIGURE 5 is a sectional view on a vertical plane through the apparatus, the position of the section being indicated by the line 55 of FIGURE 2 but showing the label magazine in side elevation.

FIGURE 6 is a side elevational view partly in section showing the manual control lever for starting the cycle of operation.

FIGURE 7 is a diagrammatic side elevational view of the clamping arm actuating mechanism, the adjoining parts being omitted to clarify the showing.

FIGURE 8 is a side elevational view in diagrammatic form showing the operating mechanism for controlling the movement of the folding blade.

FIGURE 9 is a dagrammatic perspective view showing the apparatus as it appears after the bag has been clamped but before the start of the label folding operation.

FIGURE 10 is a view similar to FIGURE 9 showing the arrangement of parts at the completion of the label folding operation.

FIGURE 11 is a view similar to FIGURES 9 and 10 showing the arrangement of parts as the bag is ejected from the jaws.

FIGURE 12 is a plan view of a portion of the lower jaw illustrating the position of the ejector.

FIGURE 1.3 is a plan view of the ejector removed from the remainder of the apparatus.

FIGURE 14 is a plan'view of the clamping arm illustrating the location of the air switch in projected position.

FIGURE 15 is a bottom plan view of the air switch removed from the clamping arm.

FIGURE 16 is a sectional view through the air switch, the section being taken on a horizontal plane.

FIGURE 17 is a sectional view through the jaws and through the pressure arm showing the apparatus for punching a hole in the label and bag.

FIGURE 18 is a view similar to FIGURE 3 showing the label delivery mechanism in a somewhat different position.

FIGURE 19 is a view similar to FIGURE 18 showing the label delivery mechanism in still another position.

FIGURE 20 is a perspective view of a portion of the upper end of a sealed bag showing the manner in which the label is folded over the end of the bag. 1

FIGURE 21 is an elevational view of the suction manifold designed to direct suction to the label delivery mechanism and to the lower jaw of the heat sealing mechanism.

FIGURE 22 is a diagram of the wiring of the apparatus.

FIGURE 23 is a diagram of the suction system of the apparatus.

FIGURE 24 is a cross sectional view through one of the air valves forming a part of the apparatus.

FIGURE 25 is a diagrammatic elevational view of the clutch mechanism.

FIGURE 26 is a section on the line 26-26 of FIG- URE 14. 7

FIGURE 27 is a transverse section through the label hopper or magazine.

FIGURE 28 is a sectional view through the jaws.

FIGURE 29 is a top plan view of a portion of the upper jaw, showing the coding device therein.

FIGURE 30 is a front elevational view of the coding 7 device.

FIGURE 31 is a horizontal section through the coding device.

FIGURE 32 is a perspective of the coding device hous- The heat sealing apparatus is indicated in general by the letter A. As indicated in FIGURES 1 and 5 of the drawings, the machine is mounted upon a base panel 1% which is supported in any suitable manner. A generally rectangular base frame 11 is secured to the upper surface of the panel 10 by means of bolts 12 or other suitable means. A pair of laterally spaced arms or lugs 13 project upwardly and forwardly from the base frame 11. The main frame 14 of the machine is supported by the base frame 11. The main frame 14 includes a hollow generally rectangular base portion 15, the side walls 16 of which are secured to the arms 13 by means of pivots 17 which are aligned on opposite sides of the frame.

The frame 14 projects forwardly as indicated at 19 to form a support for the fixed lower jaw 20. The jaw 2.0 is mounted upon insulation spacers 21 (see FIGURE 28). Threaded bolts 21 extend through two of the spacers 21 and are threaded into the jaw 20. The jaw 29 includes a pair of grooves 20' in its under surface, the grooves extending longitudinally of the jaw. Bolts 18 extend through spacers 21 and through the frame portion 19. The rectangular nuts 18 on the bolts 18 engage between the sides of the groove to hold the jaw in proper transverse alignment. As the bolts 21' anchoring the jaw 2% are near the center of the jaw, and fit freely enough to permit slight expansion therebetween, the jaw may expand and contract to some extent, the nuts 18' sliding in the grooves 20.

A pivot shaft 22 is supported by the sides of the frame 14, the shaft 22 extending between a pair of upwardly projecting arms 23 on opposite sides of the frame, one of which is shown in FIGURE 5. A pressure arm 24 is provided with a pair of spaced downwardly projecting arms 25 which terminate at their lower ends in bearings encircling the pivot shaft 22. A pressure cam arm 25 is provided with a bearing sleeve 27 and one end thereof accommodating a bushing 29 rotatable upon the pivot shaft 22. The pressure arm 24 is pivotally supported intermediate its front and rear ends, the arm 24 being at its forward and substantially as wide as the clamping jaws as will be seen in FIGURE 1 of the drawings. The upper clamping jaw 39 is attached to the forward end of the arm 24 by suitable means such as by bolts 31 extending through the arm 24, through insulation spacers 32, and the bolts are threaded into the upper jaw 30. The bolts 31 are near the center of the jaw 30 and fit loosely enough to permit any expansion and contraction of the jaw therebetween. The upper surface of the jaw 39 is provided with grooves 30' near the end thereof. Bolts 38 extend through the pressure arm 24 and insulation spacers 32 and are provided with nuts 38' which fit 'between the sides of the grooves 30' to hold the jaw 30 in position. 'These nuts 33' may slide in the grooves 30' upon expansion and contraction of the upper jaw.

The upper surface of the cam pressure arm 26 is pro- .vided with a socket 33- communicating with a smaller diameter opening 34 leading the remainder of the distance through the arm. An adjustment bolt 35 extends loosely through the aperture 34 and the socket 33 and is threaded into an internally threaded aperture 36 at the rear end of the pressure arm 24. A spring 37 encircles the shank of the adjustment bolt 35 within the socket 33 and an adjustment nut 39 is threaded upon the bolt 35. The bolt 35 is held from rotation in any suitable manner and by rotating the adjustment nut 39, the compression of the spring 37 may be regulated.

As is evident from FIGURE 2 of the drawings, a motor 40 is adjustably supported on a movable platform 41 for movement in a lateral direction toward and away from the apparatus and the motor 40 is provided with a variable pitch pulley 42 connected by a belt 43 to a similar parallel pulley 44 mounted upon the drive shaft 45 of a gear reduction box 46 mounted upon the machine frame 14. The speed of operation of the drive shaft 40 may be varied by varying the distance between the pulleys 42 and 44. The gear reduction box 46 drives a drive shaft 47 which extends transversely of the machine, the end of the shaft 47 being supported by a suitable bearing 49 mounted upon a vertical portion 50 of the frame 14. A clutch 51 is provided with one portion thereof keyed or pinned to the drive shaft 47 as indicated at 52,. The details of construction of the clutch 51 is not described as this clutch is not a part of the invention. However, with reference to FIGURE 25 of the drawings, the clutch 51 is actuated by a ring shaped operating element 53 pivotally connected to the clutch body at 54 and provided with a notch or shoulder 55 in its periphery. The clutch 51 operates in the direction of the arrow until the pawl or dog 56 engages in the notch 55 swinging the ring 53 into eccentric relation with the clutch and acting to disconnect the clutch so that the shaft 47, together with the body of the clutch 51 may rotate while the various other mechanisms remain stationary. When the dog 56 is disengaged from the notch 55, the clutch '51 again automatically engages to drive other rotatalble parts on the shaft as will be described.

The disengageable portion 57 is mounted upon a sleeve 59 which is rotatable relative to the shaft 47 and encircles the same. A collar 60 and a cam 61 are also mounted upon the sleeve 59 to rotate therewith.

As is indicated in FIGURE of the drawings, the cam 60 is engageable with a cam roller 62 mounted upon the end of the pressure cam arm 26. Upon rotation of the shaft 47 and the disengageable portion 57 of the clutch 51, the cam is rotated through one rotation, and acts against the cam roller 62 to swing the clamping jaw 30 against the clamping jaw 20 in a manner which will be more clearly described.

A pair of brackets 63 and 64, the latter of which forms a part of the frame member 50, are supported as a part of the frame 14 and act to form bearings for a counter shaft 65. A gear 66 is mounted upon the sleeve 59 to rotate with the shaft 47 when the clutch 51 is engaged. A cooperable gear 67 is mounted upon the counter shaft 65 to drive the shaft 65 when the clutch 51 is engaged. The shaft 65 supports a series of cams which act to drive various parts of the mechanism. The operation of each cam will be individually described.

As has been described, the clutch 51 automatically disengages each time the drive shaft 47 makes a complete revolution. This is accomplished by engagement of the dog 56 in the notch 55 of the clutch ring 53. The dog 56 is pivotally supported at 69 to a bracket 70 connected to the frame 14. A spring 71 normally urges the dog 56 into engagement with the ring 53. The dog 56 comprises one arm of the bell crank lever having a downturned arm 72. .The arm 72 is pivotally connected at 73 to an operating link 74.

The end of the link 74 is slotted as indicated at 75 to accommodate a pin 76 bridging the bifurcated end 77 of a lever arm 79 mounted upon a transverse shaft 80 supported by the frame 14. With reference now to FIG- .URES 6 and 7 of the drawings, it will be noted that a second arm 81 is also mounted upon the shaft for rotation in unison therewith. The arm 81 supports a cam roller 82. engageable with the periphery of a cam 83 mounted upon the counter shaft 65. The cam roller 82 is held against the surface of the cam 33 by means of a spring 34 which is connected to the arm 81 at 85 and which is connected to a bracket 86 by means of an adjustable bolt 87.

A clamping arm support 89 is slidably supported in a groove 90 in the side of the frame 14 and a cover plate 91 overlies the groove 90 to slidably support the arm 89. A roller 92 is mounted upon an end of the bar or arm 89 and is slidably and pivotally engaged in a slot 93 in the lever arm 81. As is perhaps best illustrated in FIGURE 14 of the drawings, the bar 89 sup ports the clamping arm 94 which is mounted parallel to the clamping jaws 20 and 30 and which is engageable with the lower clamping jaw 21} in one position of the bar 89. The clamping arm 94 is provided with a pair of generally rectangular notches 95 in its rear edge to accommodate adjustable clamping blocks 96 shown in FIGURES l4 and 26. The clamping blocks 96 are provided with laterally extending wings 97 which are slidably engaged in grooves 99 on opposite sides of the notches 95. Springs 100 are seated in the clamping blocks 96 to engage against the base of each notch 95 to urge the clamping blocks 96 outwardly. Pins 101 extend through the clamping arm 94 and through slots 101' in the wings 97 of the clamping blocks 96 to limit movement of the clamping blocks. The clamping blocks 96 are designed to engage against the upper end of a bag to be sealed to hold the bags against the lower jaw 20 during the sealing operation.

With reference now to FIGURE 6 of the drawings, as well as to FIGURE 7, it will be noted that the bar 89 is provided with a longitudinal slot 102 therein which is designed to accommodate a pin 103. The pin 103 extends through the cover plate 91 and is also supported by a bracket 104. The pin 103 is notched as indicated at 10-5 to accommodate the rounded end 106 of an operating lever 107 pivotally supported at 109 to a bracket 1103 mounted upon the side 50 of the frame 14. A plunger 110 is slidably supported by a suction cylinder [111 also mounted on the side 50 of the frame 14. A piston 112 is slidably supported within the cylinder 111 and is normally urged outwardly by a spring 113. The plunger 110 may be operated either pneumatically in a manner which will be later described or by manual pressure against a knob 114- rnounted on the end of the plunger 110. When the knob 114 is urged to the right as illustrated in FIGURE 6, the pin 103 is disengaged from the slot 102, permitting the arm 89 and the clamping arm 94 supported by the arm 89 to be drawn to the right by the spring 84.

To summarize the operation of the clamping arm- 94, it should be mentioned that the pin 103 is normally urged against the surface of the arm 89 by the spring 113 within the air cylinder 111. During the cycle of operation, the lever arm 81 is swung in a counter-clockwise direction by action of the cam 83 until the slot 102 is in registry with the pin 103 at which time the pin enters the slot 102. Thus, when the cam 83 reaches the position illustrated in FIGURE 7 of the drawings, the pin 1&3 acts as a trigger to hold the clamping arm 94 in spaced relation to the lower jaw 20 until the pin 103 is retracted from the slot 102 either by suction in the cylinder 111 or by pressure against the knob 114. When the pin 103 is retracted, the lever arm 81 can swing in a clockwise direction by the pull of the spring 84 causing the clamping arm 94 to be drawn against the lower jaw 20 to clamp the bag to be sealed against this lower jaw. Simultaneously, as noted in FIGURE 25, the shaft 80 on which the lever arm 81 is mounted will be rotated against the end 115 of the slot 75, urging the link 74 to the left as viewed in FIGURE 25 and pivoting the dog 56 out of engagement with the notch 55. It should be noted that FIGURE is viewed from one side of the apparatus while FIGURE 7 is viewed from the opposite side. When the dog 56 is released from the notch 55, the clutch 51 will engage and the appaartus will go through a cycle of operation until the dog 56 again engages the notch 55.

As indicated in FIGURE 27 of the drawings, the label hopper 116 includes a pair of side plates 117 having inwardly extending flanges 119 at their lower ends on which the labels may rest. Blocks 120 are provided on the undersurface of the flanges 119 and internally threadedapertures 121 are provided in alignment in the l as extending transversely of the machine forwardly of the hopper 116. The suction heads 162 are slidably supported on the shaft 161 and are supplied with partial vacuum from the flexible conduits 163. The suction heads 162 are designed to hold the foremost label in the hopper 116 while this label is drawn forwardly, swung downwardly in front of the jaws 20 and 30, and moved inwardly against these jaws. The path of travel of the a suction heads is diagrammatically illustrated by the broken blocks 12010 accommodate a right and left hand screw threaded shaft 122. By rotation of the shaft 122 by its operating handle 123 the blocks 120 which support the sides of the hopper may be moved closer together or farther apart to accommodate labels of dififerent sizes. The rear ends of the flanges 119 are laterally slidable in a groove 124- in a cross member 125 secured to the frame by T-headed adjustment bolts 126.

A pair of angle brackets 127 are mounted on the surface of the cross member 125 to support a pair of side plates 130. A channel shaped member 13 1 is pivotally supported between the plates 130 at 132. (See FIGURE 5.) A clamping bolt 13 3 is slidable in an arcuate slot 134 to permit angular adjustment of the channel 131 so that the incline of this channel may be changed. A

label pressing plate 135 is supported by a generally cylindrical cross bar 136 slidable on the upper edges of the hopper sides 117 and the plate 135 is connected to a cylindrical weight 137 by a connecting rod 139. The weight 137 is slidable longitudinally of the channel 131 and exerts pressure against the pressure plate 135 urging the labels forwardly. By changing the inclination of the channel 131 the pressure against the labels may be varied.

The :labels are held in the magazine by the cross bars 140 and 141 best seen in FIGURE 2 and which are supported in any of a series of vertically spaced apertures 142 seen in FIGURE 5. The upper shaft 146 includes rollers 143 of relatively large diameter which engage against the surface of the foremost label while the shaft 141 is provided with smaller diameter rollers 144. The lower ends of the labels are restrained by inwardly projecting lugs 145 which extend inwardly from opposite sides of the label. As a result of this arrangement, as the front label is pulled forwardly from the magazine, the lower edge of the label bows outwardly intermediate its ends to separate the front label from the next adjacent label.

The label transfer mechanism is perhaps best illustrated in FIGURES 3, 18 and 19 of the drawings. As shown in FIGURE 3, the mechanism includes a lever 146 which is pivotally supported at 147 to a bracket 149 mounted on the frame 14. An arm 159 is secured to the lever 146 to extend radially from the pivot 147 and a spring 151 connects the arm to a part of the frame 14 to urge the lever 146 in a counter-clockwise direction as viewed in FIGURE 3. The spring thus serves to hold a cam roller 152 on the lower end of the lever 146 against an operating earn 153. The cam 153 acts to rock the upper end of the lever 146 forwardly and rearwardly during each cycle of rotation.

An arm 154 is pivotally connected at 155 to the upper end of the lever 146 and a bracket 156 on the arm 154 supports a cam roller 157 which is engageable with a cam 159. Both of the cams 153 and 159 are mounted upon the counter shaft 65 for rotation in unison therewith. The cam 159 imparts an upwardly and downwardly extending motion to the forward end of the am 154. A leaf spring 160 engages the arm 154 to hold the cam roller 157 in contact with the cam 159.

.The forward. end of the arm 154 supports a translines 164 in FIGURE 19. FIGURE 3 of the drawings shows the label delivery arm in position forwardly of the label magazine and before the suction heads are moved inwardly against the label. FIGURE 18 shows the suction heads in label engaging position while FIGURE 19 shows the suction heads in position forwardly of the jaws and in position to deliver the label to the jaws.

As is perhaps best illustrated in FIGURE 17 of the drawings, the lower jaw 20 is provided with an air passage 165 extending transversely of the apparatus and connected by a suitable conduit, not illustrated in this figure, to a source of supply of partial vacuum. Openings 166 are provided in the forward edge of the lower jaw 20. When the label is moved into the position illustrated in FIGURE 19 of the drawings, the source of partial vacuum is connected to the passage 165 and the label is drawn against the lower jaw by suction. Shortly subsequent to this time, the supply of suction to the suction heads 162 is cut off and the suction heads swing upwardly toward the label magazine 116 to pick up the next label. A series of labels 167 are shown in FIGURE 5 in the magazine 116 and one label 167 is shown in position forwardly of the jaws.

The label 167 is folded between the jaws 20 and 30 by a folding blade 169 connected to the forward end of a slidable arm 1'70 slidably supported in. a groove 171 in the side 50 of the frame 14. As indicated in FIGURE 8 of the drawings, a cover plate 172 overlies the groove 171 to perform a closure for the groove and to complete the slidable support. A roller 173 is mounted on the end of the arm and the roller 173 is slidable in a notch or longitudinal groove 174 in a lever arm 175. The lever arm 175 is pivotally supported at 176 to a portion of the frame 14 and supports a cam roller 177 engageable with the peripheral surface of a cam 179 mounted upon the counter shaft 65. The cam 179 accordingly operates during rotation of the countershaft to draw the folding blade 169 between the partially opened jaws 20 and 30 and to urge the upper end of the bag between the jaws and to simultaneously fold the label between the jaws and in position to enclose the upper end of the bag.

A spring 180 is connected to the forward end of the arm 170 and to the bracket 86 at the rear of the machine frame 14 to hold the cam roller 177 against the earn 179. As will be later described, the cam 179 controlling the movement of the folding blade 169 as well as the cam 83 controlling the operation of the clamping arm 94, both act to urge the folding blade and clamping arm a maximum distance away from the jaws at the completion of the sealing operation and at the time the jaws are opened so as to insure the disengagement of the bag and label from the jaws without interference. At the end of the cycle of operation, the folding blade and clamping arm move toward the jaws so as to decrease the space between these members and the jaws to insure quicker action of the machine as the next cycle of operation is begun.

An ejecting device is provided on the lower jaw of the apparatus operable to forcibly eject the bags from the jaws at the completion of the sealing operation. The ejector is formed as illustrated in FIGURES 12, 13 and 17 of the drawings including a generally rectangular plate 182 having a tapered attached front portion 183 which inclines upwardlyand forwardly at the front of the fixed jaw 20 and terminates in an upturned end 184 located in a notch 185 in the forward surface of the lower jaw 29. The central part of the ejector plate is cut away as indicated at 186 so as to straddle certain of the spacers '21 between the fixed jaw 20 and its support 19. A rod 187 is connected to the rear end of the ejector plate 182 and, as indicated in FIGURE of the drawings, the rod 187 is connected by a coupling 189 to the piston plunger 199 of a suction cylinder 191. The plunger rod 190 is connected to a piston 192 in the suction cylinder 190 and the piston is urged rearwardly by a spring 193 when the cylinder is not subject to partial vacuum. When partial vacuum is connected to the cylinder 191, the piston 192 is drawn forwardly, pushing the ejector 182 forwardly of the lower jaw 20 and thereby acting to forcibly eject the bag and label from between the jaws.

A hole punching device is provided for punching a hole through the label and bag as the bag is sealed so that the bag may be hung upon a rack if desired. As indicated in FIGURE 17, an aperture 195 is provided vertically in the lower jaw 20 which supports a ring shaped bushing 196. The upper jaw 30 is provided with an aligned aperture 197 which supports a sleeve 199 having a slightly restricted lower end 290. A plunger rod 201 is provided within the sleeve 199 which acts to urge a cutting sphere 292 downwardly. The pressure arm 24 is provided with an aligned aperture 293 which accommodates the upper end of the plunger 261 and also accommodates a spring 204 which is interposed between the upper end of the plunger 261. 'An internally threaded plug 265 is threaded into the upper end of the aperture 21131 and accommodates a set screw 206 which bears against a bearing plate 297 at the upper end of the spring 294 to permit adjustment of the spring tension. It will be noted that the spring 2114 is thus mounted within the forward end of the pressure arm 24 rather than in the upper jaw 30 where the spring will be less aflected by the heat of the jaw 30.

An air switch 209, best illustrated in FIGURES 14, 15 and 16 of the drawings is adjustably supported upon the clamping bar 94. A slot 210 extends longitudinally of the clamping arm 94 and the upper end of the slot 210 is widened as indicated at 211 to accommodate a slidable mounting plate 212. A fastening bolt 213 extends upwardly through the body of the switch 209 and is threaded into the plate 212 to secure the switch 209 in an adjusted position upon the clamping arm. FIG- URE 15 of the drawings shows the switch in inverted position while FIGURES l4 and 16 show the switch as viewed from above.

The switch 299 includes a generally rectangular body having a plunger 214 slidably supported therein for movement in a direction normal to the rear edge of the clamping arm 94. The plunger 214 is provided with a transverse aperture 215 extending therethrough in which is anchored a tubular bushing 216 which is connected by a flexible conduit 218 to a source of partial vacuum. The plunger 214 supports a thin resilient flexible reed or blade 217 which is normally spaced from the end of the aperture 215 but which is capable of extending over this aperture to form a closure for the end of the aperture. A spring 219 is interposed between an end of the plunger 214 and a closure plate 224) closing the end of the chamber 221 within which the plunger 214 may slide. A bolt 219 is threaded into the plunger 214 and extends through the spring 219 and through the cover plate 220 to limit outward movement of the plunger. A resilient washer 219" encircles the outer end of the bolt 219' to cushion its engagement with the plate 220.

A second plunger 222 is slidably supported by the switch body in right angular relation to the plunger 214. The plunger 214 is provided with a notch 223 into which the plunger 222 may engage as indicated in FIGURE 15 of the drawings to hold the plunger 214 in a retracted position. The plunger 222 extends into an oval chamber 224 and is equipped with an operating piston 225 on its extremity. A spring 226 normally urges the plunger 222 into a projected position in which its end is engaged in the notch 223.

The operation of the switch 209 will be more clearly understood when the air diagram is described. However, in general, at the start of the cycle of operation, the plunger 214 is in projected position with the reed 217 in spaced relation to the suction aperture 215. When a bag is inserted between the clamping bar 94 and the lower jaw 20, the edge of the bag engages the reed 217 when the bag is in proper alignment with the label 167. The pressure of the side of the bag acts to move the reed 217 against the end of the aperture 215 and the air which is being drawn inwardly through the aperture 215 is cut off which functions in a manner later described to operate the piston 112 in the suction cylinder 111 thus automatically starting the apparatus into a cycle of operation. At the start of this cycle, the clamping bar 94 is drawn against the lower jaw 20 and the plunger 214 engages the jaw 21 and is retracted thereby until the plunger 214 is latched in retracted position as shown in FIGURE 15. The plunger .214 remains latched in retracted position throughout most of the remainder of the cycle of operation, holding the switch retracted until after the bag and label have been ejected from between the clamping jaws. At this point in the operation, partial vacuum is supplied through a conduit 227 leading to the chamber 224 moving the piston 225 to the right. as viewed in FIGURE 16 and releasing the latching plunger 222 from the notch 223 in the plunger 214. When released, the plunger 214 is projected from its housing by the force of the spring 219.

As indicated in FIGURE 4 of the drawings, a pair of air valves 229 and 230 are mounted upon the frame '14 beneath the counter shaft 65 and cams 231 and 232 are mounted upon the counter shaft 65 to actuate these valves 229 and 230 in proper timed relation to the sequence of operation. The valve 229 controls the partial vacuum to the ejector cylinder 191 while the valve 230 controls the introduction of partial vacuum to the piston chamber 224 to release the latching plunger 222 from the switch plunger 214 to permit the plunger 214 to move into projected or operative position.

A suction controlling manifold 233 encircles the counter shaft 65 and is held from rotation by a slightly flexible link 234 extending through an aperture 235 in a bracket 236 mounted upon the frame 14 and held in an adjusted position by a set screw 237. The link 234 includes a right angularly extending end 239 which engages into the manifold 233. The manifold 233 is in abutting relation to the cam 153 which partially actuates the label delivery arm 154 which has been previously described. The manifold 233 is provided with a radial passage 240 which communicates with a pair of laterally extending passages 241 and 242 which are in radially spaced relation. The passage 249 communicates with a Y-shaped fitting 243 which leads to a source of supply of partial vacuum as will be described. The manifold 233 also includes a radial passage 244 which communicates with a lateral passage 245 which is at the same radius as the lateral passage 241. The manifold 233 also includes a generally radial passage 246 which communicates with a lateral passage 247 which is at the same radius as the passage 242.

The surface of the cam 153 against which the manifold 233 abuts includes a pair of arcuate grooves 249 and 250. The outer groove 249 is at the same radius as the passages 241 and 245 and thus forms a communication between these two passages when the groove 249 is in registry with these passages 241 and 245. The inner arcuate groove 250 is at the same radius as the passages 242 and 247 and forms a communication between these passages when in registry therewith.

The radial passage 244 is connected toa fitting 251 provided with a pair of branches 252 and 253. The

1 1 generally radial passage 246 is connected to a T-shaped fitting 254 including a pair of branches 255 and 256.

With reference now to FIGURE 23 of the drawings, it will be noted that a source of partial vacuum is provided which is indicated as the vacuum pump 257 connected by a conduit 259 to the fitting 243. The fitting 243 is provided with a second branch 260 connected by a conduit 261 to the valve 230 and through the connection 262 to the valve 229. The valve 229 is connected by the conduit 2-63 to the ejector cylinder 191. The valve 230 is connected by the conduit 264 to the air aperture 215 of the air switch 209. The connection 264 also includes a T-connection 265 leading to the suction cylinder 111.

The fitting 251 of the manifold 233 has its branches 252 and 253 connected by flexible conduits 163 to the suction heads 162. The fitting 254 has one branch 255 connected by a conduit 266 to the conduit 165 in the lower jaw 20 and has its other branch 256 connected by a conduit 267 to the piston chamber 224 which acts to release the latching plunger 222 from engagement with the switch plunger 214.

The wiring of the apparatus is shown in simplified form in FIGURE 22. The line wire 269 is connected through a switch 270 to the drive motor 40, the other terminal of which in connected to the second line wire 271. An indicator light 272 is connected in parallel with the motor 40 to provide an indication when the motor is in operation.

The line wire 269 is connected through a second switch 273 to the pump motor 274, the second terminal of which in connected to the second line wire 271. An indicator light 275 is connected in parallel with a motor 274 to indicate when this motor is in operation.

A third switch 276 is connected through a thermostatic switch 277 to heating elements 279 and 280 which are located in the jaws 2t) and 30. An indicator light 281 is connected in parallel to the resistance elements 279 and 280 to indicate when the thermostatic switch 277 and operating switch 276 are both closed.

The operation of the apparatus is as follows: The switch 276 is closed for a sufficient time to permit the heating elements 279'and 280 to heat the jaws to the proper temperature. The pump motor 274 is started to provide a source of partial vacuum and the switch 279 is closed to start the motor 40. When the motor 40 is started, the dog or pawl 56 is in engagement with the notch 55 of the control ring 53 so that the drive shaft 47 will be operated but the various cams will remain stationary.

During its inactive period, the label which has been carried in position forwardly of the jaws during the preceding cycle will drop from the suction heads due to lack of partial vacuum so the apparatus is operated through its first cycle to bring a label into proper position. This may be done by forcing inwardly the knob 114 of the plunger 11!) of the vacuum cylinder 111 illus trated in FIGURE 6. This action will retract the pin 103 from the arm 89 releasing the clamping bar and permitting the spring 84 to draw the clamping bar 24 against the lower jaw 26 thereby gripping the upper end of the bag 2211 if any such bag is in position between the clamping bar and the jaws. Usually in this first cycle of operation, no bag is employed.

Pivotal movement of the lever arm 81 caused by the release of the pin Hi3 will act to pivot the arm 79 (see FIGURE 25) in a counterclockwise direction as viewed in this figure moving the link 74 to the left and swing the pawl 56 downwardly out of engagement with the notch 55. As soon as the pawl is disconnected, the clutch is engaged and will rotate the various cams through one complete revolution until the pawl 56 again engages into the notch 55.

The groove 249 in the cam 153 which controls the partial vacuum to the suction head is so timed that as the suction heads are brought against the foremost label, the

label will be drawn to the suction heads and the source of partial vacuum will continue until the cams 153 and 159 have moved the label forwardly, swung it downwardly in front of the jaws, and moved the label inwardly toward the jaws. At this stage of the operation, the cam 153 will move into position so that the shorter groove 250 will provide a connection from the suction source to the fitting 254. At this point, the label will be drawn against the lower jaw by the suction passages in this jaw and suction will be communicated to the chamber 224 of the air switch 209 permitting the switch plunger 214 to move into projected position. The suction to the suction heads is cut off about the same time that suction is communicated to the lower jaw and as a result the suction heads are disengaged from the label and the cam swings the label pickup arm upwardly so it is clear of the clamping arm and folding blade.

It is at approximately this point that the cycle of operation is complete.

It will be seen that the label is now being supported forwardly of the jaws in sealing position. In order to fold the label over the top of the bag, a bag is inserted between the clamping arm and the lower jaw and moved laterally until the edge of the bag engages the thin flexible reed 217, flexing this reed into position to cover the air passage 215. It will be noted that at this point, the valve 230 is being held open by its cam 232 so that the connection 264 is subject to partial vacuum. As long as the opening 215 is open, the piston 112 in the suction cylinder 1 11 will remain motionless. However, as soon as the opening 215 is closed, the partial vacuum will operate to move the piston 112 against the tension of the spring 113. Movement of the plunger will act in the manner described to retract the pin 103 releasing the clamping arm from its latched position and causing the clamping arm to engage the bag and hold it against the lower jaw. This movement also acts in the manner described to release the dog 56 from engagement with the clutch operating collar thus starting a new cycle of operation.

During each cycle of operation, the clamping arm first engages the bag so that the hands of the operator are free to pick up another bag. The folding blade 169 is then moved between the partially open jaws folding the label intermediate its top and bottom edges and forcing the upper end of the bag between the sides of the label. The blade is then retracted and the jaws are closed applying a sealing pressure to the bag to seal the bag closed and to seal the label to the bag. A hole is punched through the label and bag by the punching device described and if desired a suitable marking is applied to the bag by a code device which has not been described.

'At the completion of the sealing operation, the jaws are spread apart an abnormal amount so as to insure the disengagement of the bag and label from between the jaws and at the same time the clamping arm and folding blade are moved away from the jaws an abnormal amount to provide plenty of clearance for the dropping of the bag. It will also be noted that as the clamping arm moved against the jaw, the plunger 214 of the air switch 209 was moved into retracted position by engagement with the lower jaw 20 and the plunger was held in retracted position by the latching plunger 222. At the end of the cycle of operation, the folding blade moves partially toward the jaw, the clamping arm moves a part of its distance toward the lower jaw, and the jaws swing partially closed so as to permit just enough room to permit the folding blade to fold the label over the bag end in the next cycle of operation. Just as the cycle ends, suction is applied to the lower jaw to hold the label, and suction is also transmitted to the air switch retracting the latching plunger 222 and permitting the switch plunger 214 to move into projected position for engagement with the next bag.

As indicated in FIGURE 24 of the drawings, the valves 229 and 230 include a hollow stem 290 which communicates with a transverse pasage 291 in the valve stem which is open to atmosphere when the valve is closed. As a result, the piston in the ejecting cylinder 191 will return to its normal position as soon as the valve 229 is closed. Similarly, the piston 112 in the suction cylinder 111 will return to normal position when the valve 230 is closed and the reed 217 of the air switch 209 will also spring back into its normal position spaced from the aperture 215.

It will be seen that the apparatus functions automatically through a complete cycle of operation each time a bag is inserted between the jaws and the folding blade and that as each cycle of operation starts, the bag will be clamped and held in place so that the hands of the operator are free to pick up a new bag as soon as the cycle starts. This arrangement has been successful in more than doubling the output of a single operator in a machine of this type. Due to the fact that the bag is automatically ejected near the end of the cycle, and a new label is delivered into folding position, the next cycle can start as soon as the bag is in place.

The device for providing a code mark upon the label is illustrated in FIGURES 29, 30 and 31 of the drawings. The coding device 292 is mounted in a generally rectangular notch 293 in the forward edge of the upper jaw. A pair of washers 294 hold the device 292 engaged in the notch. The washers are held in place by machine screws 295.

The coding device includes a housing 296 which is of proper outside dimensions to fit into the notch 293. The major portion of the housing is somewhat thicker than the dimensions of the notch 293 and projects forwardly from the jaw 30. The side edges 297 of the housing are of reduced thickness to extend substantially flush with the front surface of the jaw 30. The washers 294 overlie these side edges to hold the housing from forward movement out of the notch. Set screws 299 extend through the housing 296 and bear against the rear of the notch to hold the housing from vertical movement in the notch.

The upper ends of the housing sides are notched as indicated at 300 to provide horizontal shoulders. Set screws 301 extend vertically through the portion of the jaw 30 above the housing sides 297 and bear agaist the shoulders provided by the notches 300 to adjust the vertical height of the housing.

A generally rectangular recess 302 is provided in the rear side of the housing 296, and is of proper size to accommodate a series of type bars 303 in side by side relation. As noted in FIGURE 30, the lower ends of these bars 303 extend slightly below the undersurface of the jaw 30. The area of the lower jaw 20 opposite the type bars 303 may be slightly recessed, as indicated at 304.

A socket 305 is provided in one side 297 of the housing 296 on a horizontal axis. A plunger 306 is slidably supported in the socket 305 and includes a plunger rod 308 extending through the base of the socket and into the recess 302. A spring 307 is interposed between the plunger 306 and a plug 309 at the open end of the socket.

One or more recesses 310 are provided in the jaw 30 at the base of the notch 293. These recesses are designed to accommodate magnets 311 held in place by set screws 312. Passages 313 extending through the jaw from the bases of the recesses 310, to accommodate a tool for pushing the magnets from their recesses when desired.

In operation, the desired type bars 303 are inserted in the recess 302 and are held in place by the plunger rod 308. The housing is then inserted in the notch 293 of jaw 30 by forcing the housing upwardly between the washers 294 and the base of the notch. The set screws 299 are tightened to hold the housing against the washers 294. When in place, the magnets 311 hold the type in 1% position, and assist the relatively light force of the spring 307. When removed, the housing is moved vertically, as forward movement of the housing would disengage the type bars from the housing due to action of the magnets. When the jaws are brought together, a code isimprinted into the label.

In accordance with the patent statutes, we have described the principles of construction and operation of our improvement in jaw type heat sealing machines, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that changes may be made within the scope of the following claims without departing from the spirit of our invention.

We claim:

1. A heat sealing machine including a frame, a pair of jaws, means supporting said jaws on said frame for movement toward or away from each other, jaw heating means, and clamping means supported adjacent to said jaws, said clamping means being movably supported by said frame for movement toward and away from one of said jaws, said clamping means being operable to clamp a member to be sealed by said jaws in fixed relation to said one jaw, means for moving said clamping means, and means between said clamping means and said one jaw and in the path of movement of a member to be sealed in a direction parallel to said jaws to operate said moving means.

2. A heat sealing means including a frame, a pair of jaws, means on said frame supporting said jaws, said means supporting at least one of said jaws pivotally for movement toward and away from the other jaw, a folding blade engageable with a member to be sealed to urge the same between said jaws, clamping means movably supported by said frame for movement toward and away from one of said jaws, said clamping means being engageable with an article to be sealed to hold the article in fixed relation to said last named one jaw, means for moving said clamping means, and means between said clamping means and said one jaw and in the path of movement of a member to be sealed in a direction parallel to said jaws to operate said moving means.

3. A heat sealing machine including a frame, a transversely elongated jaw secured to said frame, a second transversely elongated jaw, means pivotally supporting said second jaw for movement toward and away from first mentioned jaw, a transversely elongated clamping member, means supporting said clamping member for slidable movement toward and away from said one jaw to clamp an article to be sealed against said one jaw, a transversely elongated folding blade, means on said frame supporting said folding blade fiom a position spaced from said jaws to a position between said jaws to fold a portion of the article to be sealed between said jaws, and means for heating said jaws, and an ejector slidably supported adjacent one said jaw and engageable against an article sealed to urge the sealed portion thereof from between said jaws.

4. The construction described in claim 3 and including drive means operatively connected to said frame for sequentially operating said clamping means into clamping position, operating said folding blade to fold the article to be clamped between said jaws, urging said jaws together to seal the article to be sealed, and returning these parts to starting position, and means supported adjacent said one jaw foractuating said drive means, said last named means being actuated by movement of the article to be sealed in a direction parallel to said jaws.

5. A heat sealing machine including a frame, a pair of elongated jaws supported by said frame, means on said frame pivotally supporting at least one of said jaws for movement toward the other of said jaws, a clamping means slidably supported by said frame for movement toward and away from one of said jaws, a folding blade slidably supported by said frame for movement from a position spaced from said jaws to a position between said jaws, and means sequentially operating said clamp ing means to clamp an article to be sealed against one of said jaws, to move said folding blade into and out of position between said jaws to fold a portion of the article to be sealed between said jaws, to clamp said jaws together to seal the article therebetween, and to return said jaws to open position to complete a cycle of operation, and means supported in the path of movement of an article to be sealed when moved in a direction longitudinally of said jaws between said clamping means and said jaws to actuate said drive means.

6. The structure described in claim and including resilient means urging said clamping means into clamping position, and in which said drive means includes means for urging said clam-ping means out of clamping position at the end of each cycle of operation.

7. A heat sealing means including a frame, a fixed jaw supported by said frame, a pressure arm pivotally supported by said frame, a second jaw on said pressure arm, said pressure arm supporting said second jaw for movement toward and away from said fixed jaw, a lever pivotally supported by said frame concentrically with said pressure arm, resilient means interposed between said pressure arm and said lever arm, said resilient means being supported in substantially spaced relation from said jaws, means for heating said jaws, and means for actuating said lever about its axis, pivotal movement of said lever arm acting through said resilient means to urge said pressure arm in a direction to move said jaws together.

8. The structure described in claim 7 and in which said pressure arm is pivotally supported intermediate its ends, and in which said resilient means engages one end of said pressure arm and said second jaw is supported upon the other end of said pressure arm.

9. The construction described in claim 8 and in which means are provided for adjusting the tension of said resilient means.

10. A heat sealing machine including a frame, an elongated jaw supported by said frame, a pressure arm pivotally supported by said frame, a second jaw mounted upon one end of said pressure arm and supported thereby for movement toward or away from said first jaw, a pressure cam arm pivoted coaxially with said pressure arm, resilient connecting means connecting the other end of said pressure arm and said pressure cam arm, a clamping arm slidably supported by said frame for movement toward and away from said first jaw, said clamping arm being substantially parallel to said first jaw, a folding blade, means on said frame slidably supporting said folding blade from a position in spaced relation to said jaws to a position between said jaws, cam means engaging said clamping arm supporting means for actuating the same, a second cam means engaging said folding blade supporting means for actuating the same, cam means engaging said pressure cam arm for pivoting the same, and means connected to said cam means for actuating the same in cycles.

11. The construction described in claim 10 and including means extending between said jaws and said clamping arm in the path of movement of a member to be heat sealed to actuate said means for operating said cam operating means.

12. The construction described in claim 10 and including resilient means urging said clamping means against said first jaw and resilient means urging said folding blade between said jaws, said cams being operable to urge said clamping arm and said folding blade in the opposite direction.

13. A heat sealing machine including a frame, a first elongated jaw supported by said frame, a second elongated jaw, a pressure arm hingedly secured to said frame and supporting said second jaw for movement toward and away from said first jaw, means engaging said pressure arm to pivot the same between open and closed positions, a clamping arm, means slidably supporting said clamping arm for movement toward and away fromsaid first jaw, a folding blade supported substantially parallel to said jaws, means on said frame slidably supporting said folding arm for movement from a position in spaced relation to said blades to a position between said blades, means engageable with said clamping arm supporting means for actuating the same, means engageable with said folding arm supporting means for actuating the same, drive'means connected to said pressure arm pivoting means, said clamping arm operating means and said folding blade operating means for operating the same in timed relation, a drive member, a clutch connecting said drive member and said last named means for operating said last named means in cycles of operation, pneumatic means connected to said clutch means for actuating the same, and an air switch supported between said clamping arm and said first jaw in the path of movement in a direction longitudinally of said jaws of an article to be sealed controlling said pneumatic means.

14. The construction described in claim 13 and in which said pneumatic means includes a source of partial vacuum, and a suction cylinder including a piston actuated by partial vacuum to release said clutch, a suction line from said source of partial vacuum to said cylinder and to said air switch, said air switch including a normally open orifice through which atmospheric air may be drawn, and a flexible resilient blade normally spaced from said orifice and in the path of movement of the article to be sealed, and movable into orifice covering position, the closing of said orifice actuating the piston in said suction cylinder.

15. A heat sealing machine including a pair of elongated clamping jaws, means pivotally supporting one of said jaws for movement toward and away from the other jaw, drive means for pivoting said jaws through a cycle of operation, a clutch means interposed between said drive means and said jaws for moving said jaws through a cycle of operation, a clutch actuating member, a pneumatic cylinder, a piston within said cylinder connected to said clutch actuating device, a source of partial vacuurn connected to said cylinder for actuating the same, and an air switch supported adjacent said jaws for actuation by a member to be sealed, said air switch including an orifice connected to said source of supply of partial vacuum, a resilient blade extending in substantially right angular relation to said jaws forming a part of said switch movable into and out of position to close said orifice, said piston being normally biased out of clutch engaging position, whereby when said resilient blade overlies said orifice said partial vacuum source will actuate said piston to actuate said clutch actuating means.

16. A heat sealing machine for securing a folded label over the upper end of a bag or the like, the machine including a pair of jaws, means supporting said jaws for movement toward or away from one another, a label hopper adjustably supported on said frame, a feed device including suction cup means engageable with the label to remove the same from the hopper and means for moving said label engaging means forwardly from said hopper and then from a position forwardly of the hopper to a position forwardly of the jaws, means on one of said jaws for securing the label in position forwardly of the jaws, and a folding blade movably supported adjacent said jaws for folding the label between said jaws.

17. The construction described in claim 16 and in which said means retaining the label forwardly of the jaws includes suction means.

18. The construction described in claim 16 and includ ing a plurality of connected apertures in one of said jaws, a source of partial vacuum, and means connecting said source of partial vacuum to said connected openings to draw said label against said one jaw. V i

19. The construction described in claimlS and including means operable in cycles for actuating said jaws 17 toward and away from each other and including control means operable in timed relation to said actuating means for controlling the flow of air through said connecting means.

20. The construction described in claim 16 and in which said label hopper includes spaced sides, a member bridging said sides and resting thereupon engageable with the labels in said hopper, an inclined guide supported rearwardly of said hopper, a weight slidable on said inclined guide, and means connecting said weight and said member bridging said sides to urge said last named member against said labels.

21. A heat sealing machine including a pair of jaws, means supporting said jaws, for movement toward and away from each other, said jaws being elongated and being secured intermediate their ends to said supporting means,

and means slidably engaging the ends of said jaws for longitudinal slidable movement, whereby said jaws may expand and contract longitudinally.

References Cited in the file of this patent UNITED STATES PATENTS 2,006,060 Shilder et a1 June 25, 1935 2,140,117 Salfisberg Dec. 13, 1939 2,339,304 Haase Jan. 18, 1944 2,348,196 Duhaime May 9, 1944 2,591,935 Heigl Apr. 8, 1952 2,659,520 Reitzes Nov. 17, 1953 2,723,775 Hofe et a1 Nov. 15, 1955 2,751,965 Miller June 26, 1956 2,837,979" Vilutis June 10, 1958 

